Water-resources activities of the U.S. Geological Survey in Iowa consist of collecting hydrologic data and conducting interpretive studies. Hydrologic investigations in Iowa are made through three basic types of projects: (1) hydrologic data-collection programs; (2) local or areal studies; and (3) statewide or regional investigations. These projects are funded through cooperative joint-funding agreements with Federal, State, and local agencies and direct Federal funds. The data and the results of the interpretive studies are published or released by either the U.S. Geological Survey or by cooperating agencies. This report describes: (1) the hydrologic data-collection programs; (2) the local or areal hydrologic investigations; and (3) statewide or regional studies conducted by the U.S. Geological Survey in Iowa during fiscal year 1992 and provides a list of selected water-resources references for Iowa.